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Milena Nasi Sara De Biasi Elena Bianchini Lara Gibellini Marcello Pinti Tiziana Scacchetti Tommaso Trenti Vanni Borghi Cristina Mussini Andrea Cossarizza 《PloS one》2015,10(1)
Background
An accurate and affordable CD4+ T cells count is an essential tool in the fight against HIV/AIDS. Flow cytometry (FCM) is the “gold standard” for counting such cells, but this technique is expensive and requires sophisticated equipment, temperature-sensitive monoclonal antibodies (mAbs) and trained personnel. The lack of access to technical support and quality assurance programs thus limits the use of FCM in resource-constrained countries. We have tested the accuracy, the precision and the carry-over contamination of Partec CyFlow MiniPOC, a portable and economically affordable flow cytometer designed for CD4+ count and percentage, used along with the “CD4% Count Kit-Dry”.Materials and Methods
Venous blood from 59 adult HIV+ patients (age: 25–58 years; 43 males and 16 females) was collected and stained with the “MiniPOC CD4% Count Kit-Dry”. CD4+ count and percentage were then determined in triplicate by the CyFlow MiniPOC. In parallel, CD4 count was performed using mAbs and a CyFlow Counter, or by a dual platform system (from Beckman Coulter) based upon Cytomic FC500 (“Cytostat tetrachrome kit” for mAbs) and Coulter HmX Hematology Analyzer (for absolute cell count).Results
The accuracy of CyFlow MiniPOC against Cytomic FC500 showed a correlation coefficient (CC) of 0.98 and 0.97 for CD4+ count and percentage, respectively. The accuracy of CyFlow MiniPOC against CyFlow Counter showed a CC of 0.99 and 0.99 for CD4 T cell count and percentage, respectively. CyFlow MiniPOC showed an excellent repeatability: CD4+ cell count and percentage were analyzed on two instruments, with an intra-assay precision below ±5% deviation. Finally, there was no carry-over contamination for samples at all CD4 values, regardless of their position in the sequence of analysis.Conclusion
The cost-effective CyFlow MiniPOC produces rapid, reliable and accurate results that are fully comparable with those from highly expensive dual platform systems. 相似文献44.
Giuseppe Vannozzi Silvia Conforto Tommaso D’Alessio 《Journal of electromyography and kinesiology》2010,20(4):767-772
The problem of the identification of the muscle contraction timing by using surface electromyographic signal is addressed. The timing detection of the muscular activation in dynamic conditions has a real clinical diagnostic impact. Widely used single threshold methods still rely on the experience of the operator in manually setting that threshold. A new approach to detect the muscular activation intervals, that is based on discontinuities detection in the wavelet domain, is proposed. Accuracy and precision of the algorithm were assessed by using a set of simulated signals obtaining values lower than 11.0 and 8.7 ms for biases and standard deviations of the estimation, respectively. Moreover an experimental application of the algorithm was carried out recruiting a population of 10 able-bodied subjects and processing the myoelectric signals recorded from the lower limb during an isokinetic exercise. The algorithm was able to reveal correctly the timing of muscular activation with performance comparable to the state-of-the-art methods. The detection algorithm is automatic and user-independent, it manages the detection of both onset and offset activation, it can be fruitfully applied even in presence of noise and, therefore, it can be used also by unskilled operators. 相似文献
45.
Federica Sinibaldi Barry D. Howes Maria Cristina Piro Fabio Polticelli Cecilia Bombelli Tommaso Ferri Massimo Coletta Giulietta Smulevich Roberto Santucci 《Journal of biological inorganic chemistry》2010,15(5):689-700
Two models have been proposed to explain the interaction of cytochrome c with cardiolipin (CL) vesicles. In one case, an acyl chain of the phospholipid accommodates into a hydrophobic channel of
the protein located close the Asn52 residue, whereas the alternative model considers the insertion of the acyl chain in the
region of the Met80-containing loop. In an attempt to clarify which proposal offers a more appropriate explanation of cytochrome
c–CL binding, we have undertaken a spectroscopic and kinetic study of the wild type and the Asn52Ile mutant of iso-1-cytochrome
c from yeast to investigate the interaction of cytochrome c with CL vesicles, considered here a model for the CL-containing mitochondrial membrane. Replacement of Asn52, an invariant
residue located in a small helix segment of the protein, may provide data useful to gain novel information on which region
of cytochrome c is involved in the binding reaction with CL vesicles. In agreement with our recent results revealing that two distinct transitions
take place in the cytochrome c–CL binding reaction, data obtained here support a model in which two (instead of one, as considered so far) adjacent acyl
chains of the liposome are inserted, one at each of the hydrophobic sites, into the same cytochrome c molecule to form the cytochrome c–CL complex. 相似文献
46.
Agostini T Lazzeri D Pascone C Agostini V 《Plastic and reconstructive surgery》2010,126(5):1787-8; author reply 1788-9
47.
Lazzeri D Pascone C Agostini T 《Plastic and reconstructive surgery》2010,126(5):1793-4; author reply 1794
48.
Nina Desai Anastasia Alex Faten AbdelHafez Anthony Calabro James Goldfarb Aaron Fleischman Tommaso Falcone 《Reproductive biology and endocrinology : RB&E》2010,8(1):119
In vitro ovarian follicle culture is a new frontier in assisted reproductive technology with tremendous potential, especially
for fertility preservation. Folliculogenesis within the ovary is a complex process requiring interaction between somatic cell
components and the oocyte. Conventional two-dimensional culture on tissue culture substrata impedes spherical growth and preservation
of the spatial arrangements between oocyte and surrounding granulosa cells. Granulosa cell attachment and migration can leave
the oocyte naked and unable to complete the maturation process. Recognition of the importance of spatial arrangements between
cells has spurred research in to three-dimensional culture system. Such systems may be vital when dealing with human primordial
follicles that may require as long as three months in culture. In the present work we review pertinent aspects of in vitro
follicle maturation, with an emphasis on tissue-engineering solutions for maintaining the follicular unit during the culture
interval. We focus primarily on presenting the various 3-dimensional culture systems that have been applied for in vitro maturation
of follicle:oocyte complexes. We also try to present an overview of outcomes with various biomaterials and animal models and
also the limitations of the existing systems. 相似文献
49.
The impact of neutrality, niche differentiation and species input on diversity and abundance distributions 总被引:4,自引:1,他引:3
We present a spatially-explicit generalization of Hubbell's model of community dynamics in which the assumption of neutrality is relaxed by incorporating dispersal limitation and habitat preference. In simulations, diversity and species abundances were governed by the rate at which new species were introduced (usually called 'speciation') and nearly unaffected by dispersal limitation and habitat preference. Of course, in the absence of species input, diversity is maintained solely by niche differences. We conclude that the success of the neutral model in predicting the abundance distribution has nothing to do with neutrality, but rather with the species-introduction process: when new species enter a community regularly as singletons, the typical J-shaped abundance distribution, with a long tail of rare species, is always observed, whether species differ in habitat preferences or not. We suggest that many communities are indeed driven by the introduction process, accounting for high diversity and rarity, and that species differences may be largely irrelevant for either. 相似文献
50.